Fix deprecation notice of InfluxDB

doc/administration/monitoring/performance/gitlab_configuration.md

@@ -32,7 +32,7 @@ have been performed.
 
 Read more on:
 
-- [Introduction to GitLab Performance Monitoring](introduction.md)
+- [Introduction to GitLab Performance Monitoring](index.md)
 - [InfluxDB Configuration](influxdb_configuration.md)
 - [InfluxDB Schema](influxdb_schema.md)
 - [Grafana Install/Configuration](grafana_configuration.md)

doc/administration/monitoring/performance/grafana_configuration.md

 # Grafana Configuration
 
+CAUTION: **InfluxDB is deprecated in favor of Prometheus:**
+InfluxDB support is scheduled to be removed in GitLab 13.0.
+You are advised to use [Prometheus](../prometheus/index.md) instead.
+
 [Grafana](https://grafana.com/) is a tool that allows you to visualize time
 series metrics through graphs and dashboards. It supports several backend
 data stores, including InfluxDB. GitLab writes performance data to InfluxDB
@@ -152,7 +156,7 @@ For more information and further mitigation details, please refer to our [blog p
 
 Read more on:
 
-- [Introduction to GitLab Performance Monitoring](introduction.md)
+- [Introduction to GitLab Performance Monitoring](index.md)
 - [GitLab Configuration](gitlab_configuration.md)
 - [InfluxDB Installation/Configuration](influxdb_configuration.md)
 - [InfluxDB Schema](influxdb_schema.md)

doc/administration/monitoring/performance/influxdb_configuration.md

 # InfluxDB Configuration
 
-CAUTION: **InfluxDB is being deprecated in favor of Prometheus:**
-InfluxDB support is scheduled to be dropped in GitLab 13.0.
+CAUTION: **InfluxDB is deprecated in favor of Prometheus:**
+InfluxDB support is scheduled to be removed in GitLab 13.0.
 You are advised to use [Prometheus](../prometheus/index.md) instead.
 
 The default settings provided by [InfluxDB] are not sufficient for a high traffic
@@ -182,7 +182,7 @@ That's it! Now your GitLab instance should send data to InfluxDB.
 
 Read more on:
 
-- [Introduction to GitLab Performance Monitoring](introduction.md)
+- [Introduction to GitLab Performance Monitoring](index.md)
 - [GitLab Configuration](gitlab_configuration.md)
 - [InfluxDB Schema](influxdb_schema.md)
 - [Grafana Install/Configuration](grafana_configuration.md)

doc/administration/monitoring/performance/influxdb_schema.md

@@ -95,7 +95,7 @@ Depending on the event type additional tags may be available as well.
 
 Read more on:
 
-- [Introduction to GitLab Performance Monitoring](introduction.md)
+- [Introduction to GitLab Performance Monitoring](index.md)
 - [GitLab Configuration](gitlab_configuration.md)
 - [InfluxDB Configuration](influxdb_configuration.md)
 - [Grafana Install/Configuration](grafana_configuration.md)